This section provides background information related to the present disclosure, which is not necessarily prior art.
With reference to prior art FIG. 1, a heating, ventilation, and air conditioning (HVAC) assembly 10 is illustrated. The HVAC assembly 10 generally includes an evaporator 12 and a blower 14 including a front blower portion 14a and a rear blower portion 14b. The front and rear blower portions 14a and 14b are separated by a separator 16, such as a separator plate. The front and rear blower portions 14a and 14b generate airflow, which passes through the evaporator 12 and to a front HVAC portion 18 and/or a rear HVAC portion 20 generally depending on a position of an airflow directional door 30. The front HVAC portion 18 includes portions of the HVAC assembly 10 that provide airflow to a front portion of a vehicle in which the HVAC assembly 10 is installed. The rear HVAC portion 20 includes portions of the HVAC assembly 10 configured to provide airflow to a rear of the vehicle in which the HVAC assembly 10 is installed.
The door 30 is on a side of the evaporator 12 opposite to the blower 14. The door 30 includes a distal end 32, which is spaced apart from the evaporator 12 at any suitable distance to permit rotation of the door 30 without contacting the evaporator 12. The door 30 is configured to move between a first position A, a second position B, and a third position C. The first position A is generally intermediate to the second and the third positions B and C. In the first position A the door 30 is generally aligned with the separator plate 16. The door 30 can be moved to any suitable position between the second and the third positions B and C.
In the first position A, the door 30 extends generally perpendicular to the evaporator 12, and defines a gap or space Xa between the distal end 32 of the door 30 and the evaporator 12. The gap Xa may be any suitable size. For example, the gap Xa may be 5 mm. In the first position A, airflow generated by the front blower portion 14a passing through the evaporator 12 is generally entirely directed to the front HVAC portion 18 by the door 30, and airflow generated by the rear blower portion 14b passing through the evaporator 12 is generally entirely directed to the rear HVAC portion 20 by the door 30. Only a negligible amount of airflow passes, if any, from the front blower portion 14a across the distal end 32 of the door 30 to the rear HVAC portion 20. Likewise, only a negligible amount of airflow, if any, passes from the rear blower portion 14b across the distal end 32 of the door 30 to the front HVAC portion 18. The first position A is typically referred to as a normal position.
From the first position A the door 30 can rotate to the second position B or the third position C, or any position therebetween. The second position B is generally a front bias position. In the second position B, airflow from the front blower portion 14a is generally entirely directed to the front HVAC portion 18, and most, but not all, airflow from the rear blower portion 14b is also directed to the front HVAC portion 18. Due to a gap or space Xb between the distal end 32 and the evaporator 12, however, some airflow from the rear blower portion 14b will flow around the door 30 to the rear HVAC portion 20. In some instances, the gap Xb can be as large as 15 millimeters. Because the gap Xb is larger than the gap Xa, a pressure differential may be created between the front and rear HVAC portions 18 and 20, which may further cause airflow to pass around the distal end 32 of the door 30 to the rear HVAC portion 20 when in the second position B.
In the third position C, airflow from the rear blower portion 14b is generally entirely directed to the rear HVAC portion 20, and some, but not all, airflow from the front blower portion 14a is also directed to the rear HVAC portion 20. The third position C is generally a rear bias position. Due to a gap or space Xc between the distal end 32 and the evaporator 12, however, airflow from front blower portion 14a will undesirably flow around the door 30 to the front HVAC portion 18. In some instances, the gap Xc can be as large as 10 millimeters. Because the gap Xc is different than each of the gaps Xa and Xb, a pressure differential may be created between the front and rear HVAC portions 18 and 20, which may further cause airflow to undesirably pass around the distal end 32 of the door 30 to the front HVAC portion 18 when in the third position C.
Because the gaps Xa, Xb, and Xc are each different, the distance between the distal end 32 of the door 30 and the evaporator 12 varies depending on whether the door 30 is in first position A, second position B, third position C, or any position therebetween. In order to control airflow leakage from a high pressure side to a low pressure side of the HVAC assembly 10, it would be desirable to keep the distance between the evaporator 12 and the distal end 32 of the door 30 constant as the door 30 rotates between the positions A, B, and C, as well as any position therebetween. It would also be desirable to reduce or eliminate the gap Xa-Xc between the evaporator 12 and the distal end 32 of the door 30 to restrict airflow from undesirably passing around the distal end 32, such as when the door 30 is in position B or position C.